Signaling system



Nov. 22, 1938. s. BEGUN ET AL SIGNALING SYSTEM Filed April 29, 1956 INVENTOR. Q F'- Dursf 22 Ba up Patented Nov. 22, 1938 SIGNALING SYSTEM Semi Joseph Begun, New York, IrvingFowler Durst, Great Neck, and Herbert Barnett, New York, N. Y., assignors, by mesne assignments, to Carll Tucker, New York, N. Y.

Application April 29, 1936, Serial No. 76,958

16 Claims.

More specifically, this invention consists in a selective signaling system having a plurality of sound reproducing devices connected thereto, all

of which may be operated by one or more signal sources, and all of which may be selectively removed from circuit by the transmission of control currents over the system in addition to the signaling current and of characteristics to efiect the selective connection and disconnection of the reproducing devices to and from the system.

Still more specifically an object of this invention is to provide an arrangement such as that described above for use in connection with grounded closed impedance signaling networks such as disclosed in United States Patent No. 2,023,857 issued December 10, 1935.

These and many other objects, as will appear from the following description, are secured by means of this invention.

This invention resides substantially in the combination, construction, arrangement, relative location of parts, steps and series of steps, all as will be set forth in full detail in the following description.

In the accompanying drawing,

Figure l is a diagrammatic view of one form of system employing a grounded impedance loop;

loop grounded signal responsive devices. The sig-' nal sources may consist of radio receiving apparatus, microphones, phonographs, and the like for feeding signal energy into the network. The receiving apparatus in the event that a plurality of signal sources are employed, consists of simple radio receivers or other equivalent adjustable to every operation by the energy from any one of the sources.

An important object of this invention is to provide control apparatus for the receiving devices connected thereto singly or in groups for cutting the receiving apparatus in and out of circuit. There are in addition to the above mentioned sources of signal energy sources of control energy connected to the network for selectively operating the control apparatus for the receiving devices.

Another important object of this invention is to provide a system of this type which is particularly adaptable to be used on shipboard where in an emergency the ofllcers in charge may issue instructions to the crew or particular portions of the crew without disclosure thereof to the passengers, and under desired circumstances issue instructions or information to the passengers to the exclusion of .the crew or portions thereof.

As will be apparent from the following description and clear to those skilled in the art, the receiving apparatus may be connected in various combinations so that they may be connected and. disconnected either singly or in groups. A basic feature of this invention is the use of control currents for operating the control apparatus which do not interfere with the normal operation of the receiving apparatus .and which in turn are not operated by the signal energy.

Referring to Figure 1, there is indicated in dotted lines the framework of a structure such as a building or a ship, which may or may not be made of steel. It is immaterial whether or not the structure is of steel in the particular system disclosed in Figure 1. This structure has been shown divided up into separate rooms or spaces. At 2 is a feeder which connects together the conductors l8, I9 and 20 which extend 1 through the respective floors of the structure and are all grounded as indicated at 2|. It is not at all necessary that the conductors l8, l9, and 20 be grounded, although the system works equally well whether they are or are not grounded. In accordance with the disclosure in the above mentioned patent the conductors l8, l9 and 20 may be part of the steel framework of the buildof signal energy comprising the microphone 3, i which feeds into any suitable form of amplifying device 4. This amplifying device is grounded at I and is connected to the common feeder 2 through a condenser III. This condenser is of a capacity to pass the signal currents from the amplifier 4.

It may be noted that the microphone I is also intended to represent other suitable forms of sig-- nal energy such as the magnetic pick-up of a phonograph or a radio receiving set, the output of which would be fed into the amplifier 4. It is to be noted that several of these different types of signal sources may be connected to the am-.

pliiier or each may be provided with its own grounded amplifier connected to the common feeder 2. In other words, a plurality of signal currents may be impressed upon the network simultaneously if sufliciently separated in frequency so as not to cause interference. At 5 and I are oscillators each tuned to a different frequency and connected to the input of the amplifier so that control currents of different frequencies and different from those of the signal currents may be applied to the network. The oscillators 5 and I are provided with control switches 8 and. 8 respectively so that they may be selectively connected in circuit.

Another source of signal energy is shown comprising a battery ll connected to a double pole, double throw switch I 2. This switch is connected as a reversing switch so that the common feeder 2 may be polarized either positive or negative as desired. To accomplish this two of the contacts of the switch are connected through choke coil I4 to the common feeder 2 and two of them are grounded as at l3. Those skilled in the art will see that at one position of switch l2 the positive pole of the battery i I is connected to the common feeder and in its other position the negative pole is connected to the common feeder. In each case the other pole of the battery is grounded at I8. Choke coil I4 prevents the alternating currents from the other sources from being short circuited to ground at l3 when switch I2 is closed.

At I5 is still another source of control energy as for example generating currents of lower fre quencies than those generated by the oscillators 5 and I. This generator i5 which may for the purposes of this disclosure be termed a low frequency generator, is shown grounded at l6 and connected to the common feeder 2 through condenser I5'. It is shown provided with three control circuits selectively operable to impress any one of three low frequencies between the common feeder and ground. Condenser I5 prevents the short circuiting of current source i I through the generator i5. I

Connected to the impedance network comprising the feeder 2 and grounded conductors I8, is and 28 are a series of reproducing devices 22, 21, 82, 88,- 40, 44 and 49, all of which are con-- nected to ground through a condenser. These reproducing devices may be loud speakers or complete radio receiving sets including loud The speakers or sound reproducing devices 82, 38 and 40 are connected to the conductor I8 and to ground through condensers as shown. They are respectively shunted by switches 32, 31 and 4|. These switches are respectively operated by magnets 84, 38 and 42. Each of these magnets is grounded through condenser systems 35, 39 and 48 respectively of different capacities, and hence diflerent impedances.

The speakers or sound reproducing devices 44 and 49 are connected to the conductor and individually to ground through condensers as before. They are respectively shunted by switches 45 and 50. These switches are respectively operated by magnets 48 and 5|. Magnet 48 is in series through the rectifier 41 with a resonant circuit 48 comprising an inductance and a condenser in parallel. This resonant circuit is connected between the conductor 20 and ground. Similarly, the magnet 5| is connected in series with the rectifier 52 and to the tuned circuit 58 comprising inductance and a capacity, which tuned circuit is connected between the conductor 20 and ground. The impedance of these two circuits is different so that each is operated by currents of difierent frequency. It is to be noted that all of the circuits which shunt the sound reproducing or signal responsive devices are in circuit between their respective conductors and ground through condensers the value of which is such that the various signaling currents may pass therethrough and operate the sound reprodu'cing devices. If these sound reproducing devices comprise tunable radio receiving sets employing conductors and amplifiers in accordance with common practice, it is apparent that a plurality of signals may be impressed upon the network such as a plurality of radio broadcast programs and then each signal responsive device may be tuned as desired to be operated by any one of the signal currents. Likewise, when desired either alone or in addition to the radio programs phonograph currents may be impressed on the network and speech may be impressed thereon by means of the microphone 3. The listeners at the signal responsive devices may tune them to receive any of these programs.

In a system of this type when applied on shipboard for example, it provides a network over which an oflicer of the vessel may send instructions to preselected signal responsive devices, or to all of them. Thus in an emergency an ofiicer may issue instructions for example to the engine room to the exclusion of the rest of the crew and the passengers. This is obviously highly desirable under certain circumstances where information properly given to the crew should not be disclosed to the passengers for fear of creating a panic or at least upsetting the passengers. When he wishes to send instructions to all of the stations at which the signal responsive devices are placed, he need only talk into the microphone since all switches are open and all signal responsive devices are operable. When he wishes, however, to cut particular signal responsive devices out of circuit he may do so by operating switches 6, 8, l2 and H in any desired combination. When switch I2 is in one position a signal current will go out from battery II to the network to cause switch 24 for example to close, it being assumed that magnet is polarized and the polarity of the signal current corresponding to the closed position of switch I! energizes winding 25 so as to magnetize its core and close switch i2. Thus the signal responsive device 22 is short circuited and it; as well as all similarly arranged signal responsive devices is cut out of circuit. If switch I2 is closed in its other position, switch 29 will be closed in a similar manner to cut out the circuit to signal responsive device 21 and all devices smilarly arranged. However, none of the other signal responsive devices are cut out of circuit since, the circuits for the control magnets for their switches will not pass the direct current supplied from the source If it is desired to disconnect one or more of the signal responsive devices connected to the conductor i9 one or more of the switches ll of the, low frequency generator are operated. Thus the low frequency current sent over the network out of circuit, ;'I' he same would happen to all similarly arranged signal responsive devices. If the middle switch I! is closed a lower frequency is sent over the network causing magnet 38 to be energized since the condenser system 39 is selected wlth .respect to the value of the impedance of magnet 38 so as to be resonant at that frequency. Thus switch 31 closes and signal responsive device 36 is cut out of circuit. If the lowermost switch I! is closed a still lower frequency is impressed on the network and magnet 34 is energized since condenser system 35 is selected with respect to the value ofthe impedance of magnet 34 so as to be resonant at the frequency. Thus switch 33 is closed and signal responsive device 32 is short circuited. Thus each switch cuts out one of the speakers on conductor l9 without affecting the others. course, more than one switch I! may be closed to cut out more than one of these signal responsive devices. It is of course apparent to those skilled in the art that these relays instead of being electrically tuned as disclosed in the drawing may be mechanically tuned to be selectively operated by signals of different frequencies.

Either of the signal responsive devices 44 or by operating switches 6 and 8. It may be assumed for example that when switch 6 is closed a current of a frequency is sent over the network which may pass through the rectifier 52 in sufiicient "volume to operate magnet and close switch 59. However the circuit 48, being tuned to a different frequency, the voltage, drop across it is not sufficient to operate relay 46, so that speaker 44 remains in circuit. Similarly. when switch 9 is closed magnet 46 is energized to close switch 45.

Figure 1 also shows a further feature incorporated into the system which may be selectively operated. In this case the signal responsive device is a bell, light, or other form of indicator. One of the uses of this system is to indicate an open circuit for example, and another use would be for direct signaling purposes. In Figure 1 there is shown at 96 a source of alternating cur-- rent of any suitable form which is grounded through a normally closed switch 92 and connecting to the main feeder 2 through a condenser 9|. The value of the condenser is selected so as to prevent interaction or interflow of currents between the source 90 and the other sources connected to the common feeder. Connected be- .tween the conductor l3 and ground is a tuned circuit 98 comprising an inductance and capacity vin parallel and tuned to the frequency of the source 96. Shunted across the condenser in series is a magnet winding 91 and a rectifier 95. The magnet 9'! is arranged to operate and hold open a switch 94 which is itself biased to close when magnet 91 is deenergized. Switch 94 is in series with current source 93 and the signal device 96, which has been indicated as a lamp. This series circuit is connected between conductor l8 and ground. In the normal bperatlon of this system the current sent over the network from the source 90 is of a frequency not to interfere or cause the operation of any of the other devices connected to the network. But, on the other hand, when impressed across the tuned circuit 98, the voltage drop thereacross is sufilcient to energize magnet 91, thus holding switch 94 open. If an open circuit occurs between the source 99 and the tuned circuit 98, magnet 91 will be deenergized and switch 94 will close causing the signal device 96 to operate. Thus an undesired break in the circuit is indicated.

When'switch 92 is opened it is possible to signal to the point at which the device 96 is located. Such an arrangement is particularly useful on shipboard where the signal device is operated upon the occurrence of an open circuit, indicating trouble thereon. It is of course apparent to those skilled in the art that the current source 93 should not be a form to interfere with or cause the undesired operation of any of the other selecting means. It has only been indicated in the drawing as a battery to indicate generally a current source, although it would be immaterial during the short time that the circuit to the signal device 96 is to be closed if the application of the source 93 to the network did out out one or more of the signal responsive devices, as would be the case, for example, if the current from the source 93 should operate either of the magnets 25 or 39, or even both of them. In the best practice the source 93 would be of such a nature as not to cause switches 24 and 29 to close even though the circuit to the signal device 96 is normally only closed for a short time.

It will be noted then that with the various types of control circuits disclosed a great variety of control currents may be impressed upon the network singly and in combination to selectively remove any desired combination of signal responsive devices from circuit. Those that re-' main in circuit may be operated by the signal currents as before described.

An object of this invention is to associate with a network energized with signal currents such as radio programs for example, a public address system by means of which communications maybe sent over the network either to selected stations or to all stations provided with signal responsive devices. Thus, with this arrangement, an oihcer 0n the bridge of a ship may talk only to the engine room, or to the radio room, or, when desired, to all the passengers cabins and all stations supplied with signal responsive devices. Hence, in the case of an emergency, the officer on the bridge may issue instructions and advice to i again there may be impressed upon the conductors either through the ampliiier 55, or in parallel therewith, one or more additional signals such as radio programs, electric phonograph currents, and the like. Connected between these conductors are the signal responsive devices 59 and 95 in series respectively with the condensers ii and 91 and the switches 62 and 69. Connected across these conductors is a magnet 83, the winding of which is in series with rectifier 64 and shunted by a high resistance 65. Likewise, a magnet 99 has its winding connected across the conductors in series with the rectifier III, which is shunted by the high resistance 1 I. The rectifiers are operable by current of opposite polarity. Connected across the conductors through the high choke coils I1 and I9 are the direct current sources I2 and I8. The choke coils I1 and II are of an inductance such as to provide a high impedance path for the signal currents. Direct current source I2 is connectable across the conductors 51 and 59 through the coils I1 and I9 and conductors I8 and I9 respectively by means of a double pole double throw switch I4. This switch acts as a reversing switch so that the current source I2 may be connected to the conductors 51 and 59 to make either conductor positive or negative. A second direct current source I9 is connectable in series with the source I2 to the conductors 51 and 59 by means of the double pole single throw switch I5. Switches-52 and 68 are normally open. when switch I4 is in one position switch for example is operated, and when switch 14 is in the other position, switch as is operated. When it is desired to operate both switches 52 and 59, switch I5 is closed sending suflicient current through the high resistances 55 and II to operate both relays 63 and 69.

For systems of this type when used on shipboard the arrangement of Figure 1 is highly desirable in that it employs means for short circuiting the various reproducing devices as distinguished from the arrangement where these devices are actually out out of circuit. For reasons of safety a signaling system on shipboard must always be operative. Any arrangement which employs switches for disconnecting the reproducing devices is not acceptable for use on shipboard because of the danger of the failure of the switches to work, thus rendering the devices inoperative when they are most needed. In the system oi Figure 1 the reproducing devices are always in circuit, and while they may at times operate when it is not desired to operate them because of trouble with the short circuiting systenis, this is far more desirable than any arrangement where the reproducing devices might fail to work when needed. The short circuiting arrangement of Figure 1 is highly advantageous in a System employing a low impedance network with the reproducing devices grounded through the high impedance condensers since the short circuiting of one or more of the reproducing devices does not perceptibly vary the volume of sound reproduction from the other reproducing devices.

The impaiances in circuit with the sound reproducing devices are preferably high capacity condensers such as for example electrolytic condensers whose impedance is so high that when the sound reproducing devices are short circuited the network is not grounded through an impedance suiliciently low to effect any noticeable reduction in the volume of sound produced from the other reproducing devices which are not short circuited. To look at it in another way. the high impedance of the condensers in circuit with the sound reproducing devices protects all or the other sound reproducing devices which are not short circuited against low impedance grounding, with the result that the volume reduction of the operative devices is not noticeable. Again, as pointed out above, the short circuiting arrangement is preferable from the disconnecting arrangement of Figure 2 in that the operation of the reproducing devices is not dependent upon the operability of the short circuiting switches.

The impedance of the grounded conductors I9, I 9 and is relatively'higher than the impedance in the circuits of the signal responsive devices so that energy sources are not directly short circuited to ground. In cases where it is necessaryadditional impedance may be included in the conductors I8, I9 and/or 29.

From the above description the operation 0! this system under the various possible operating conditions will be apparent.

Those skilled in the art will readily appreciate that the systems disclosed indicate the large number or various combinations which may be eiiected so that any'desired combinations of I operable signal responsive devices may be secured. We do not, therefore, desire to be strictly limited to the disclosure as given for purposes of illustration, but'rather to the scope of the appended claims.

What we seek to secure by United States Letters Patent is:

1. In a signaling system the combination comprising a grounded conductive network having inherent distributed impedance, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connectable to said network, electrically operated means for cutting said devices from operative connection with said network, and grounded means connected to said network for impressing selective control currents on the network to efiect selective operation of said electrically operated means.

2. In a signaling system the combination comprising a grounded conductive network having inherent distributed impedance, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connected to said network, electrically operated means for cutting said devices from operation by said network, grounded means connected to said network for impressing control currents on the network to effect operation of said electrically operated means, and means in circuit with said signal responsive devices of high impedance with respect to said control ourren s.

3. In a signaling system the combination comprising a conductive network, a source of signal energy connected to said network, a plurality of signal responsive devices, means for selectively connecting said devices to and disconnecting them from said network, and a plurality of current sources of different characteristics connected to said network for eflecting selective operation of said selective means.

4. In a signaling system the combination comprising a grounded conductive network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices, and grounded means connected to said network for selectively connecting said devices to and disconnecting them from said network.

5. In a signaling system the combination comprising a grounded conductive network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices, and grounded means for selectively supplying currents of differnt characteristics to said network to effect selective operation of said selective means to connect said devices as selected to the network.

6. In a signaling system of the type described the combination comprising a conductive network, a plurality of signal responsive devices each including a normally open switch connected to said network, an impedance in circuit with each device, and selective means for selectively operating said switches to connect said devices to said network in selected groups.

7. In a signaling system of the type described the combination comprising a conductive network, a plurality of signal responsive devices each including a normally open switch connected to said network, an impedance in circuit with each device, and means for selectively operating said switches to connect selected ones of said devices to said network, said means including sources of current of different characteristics selectively operable.

8. In a system of the type described the combination comprising a conductive grounded network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connected to said network, an impedance in circuit with each signal responsive device, selectively operable means for cutting said signal responsive devices in and out oi circuit, and a. plurality of -grounded current sources connected to said network for selectively supplying currents of difierent characteristics to the network to selectively operate said means.

9. In a system of the type described the combination comprising a conductive grounded network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connected to said network, an impedance in circuit with each signal responsive device, selectively operable means for cutting said signal responsive devices in and out of circuit, and means for selectively supplying current of each polarity to said network to selectively operate said means.

10. In a system oi the type described the combination comprising a conductive grounded network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connected to said notwork, an impedance in circuit with each signal responsive device, selectively operable means forcutting said signal responsive devices in and out of circuit, and means for selectively supplying currents of diflferent frequencies to said network to selectively operate said means.

11. In a public address system the combination comprising a conductive network, means for impressing voice currents on said network, a plurality of devices responsive to said voice currents connected to said network, each through an impedance, means for cutting said devices in and out of circuit, and means for selectively supplying currents of different characteristics to said network to effect selective operation of said means.

12. In a public address system the combination comprising a closed grounded conductive loop, a grounded source of signal currents connected to said loop, a plurality of grounded signal responsive devices connected to said loop each device having in circuit with it an impedance, means for cutting said devices in and out of circuit, and selectively operable means for supplying currents of difierent characteristics to the loop to effect selective operation of said means.

. 13. In a system of the type described the combination comprising a. conductive network, a source of signal energy connected to said network, a plurality of signal responsive devices 0011- nected to said network, a switch for each device for short circuiting it, magnets for operating said switches, circuits for said magnets connected to said network and including rectifiers, and means for selectively supplying currents of diiferent polarity to said network to selectively operate said magnets.

14. In a system of the type described the combination comprising a conductive network, a grounded source of signal energy connected to said network, a plurality of grounded signal responsive devices connected to said 'network through high impedances, electrically operated relays for short circuiting said devices, and selectively operable means for supplying currents to said network to effect selective operation of said means, said impedances protecting the operating devices from loss of operating current.

15. In a system of the type described the combination comprising a. low impedance conductive network, a grounded source of signal energy connected to said network, a plurality of signal responsive devices connected to said network, connections including high impedances for grounding said devices, grounded electrically operated relays .for short circuiting said devices individually, and grounded selectively operable means connected to said network for supplying currents of different characteristics thereto to effect selective operation of said relays, the operating devices remaining operative at full volume'because of the high impedance in circuit with the devices which are not operated.

l6. In a' signaling system of the type described the combination comprising a conductive network, a source of signal energy connected to said network, a plurality of signal responsive devices, means ior selectively connecting said devices to the network to effect selective operation thereof, a signal device, and means for rendering said signal device operative upon the development of an open circuit in the network.

IRVING FOWLER DURS'I'. HERBERT BARNETT. SEMI JosEPH BEGUN. 

